Following three weeks of jams touched off by the escape of terrorist Mas Selamat Kastari, the lines of cars and heavy vehicles at the border crossing have eased considerably, the Immigration and the Checkpoints Authority said on Friday.

At about 5 pm, traffic was heavy but smooth - in stark contrast to the days when trucks formed snaking lines from the Woodlands Checkpoint to the Bukit Timah Expressway, and also to Kranji.

The average waiting time for cars, buses and motorcycles in the queues is now between an hour and 90 minutes - the same as it was before checks were stepped up after Mas Selamat's Feb 27 escape, said the ICA.

Lorries and trucks get cleared between two to six hours in the queues.

While this is shorter than the 15 hours drivers claimed they had been stuck in, it is still longer than the one to three hours it took clear the checkpoint before the hunt for Singapore's most wanted man began.

At the height of the congestion in the days following Mas Selamat's breakout, queues of lorries stretched up to 10km from the checkpoint as border officers searched for the suspected Jemaah Islamiah leader.

Meanwhile, lorries entering Singapore that stayed away from the checkpoint in the days after the escape are now returning, the ICA said.

Still, the checks are here to stay - as long as Mas Selamat is believed to be hiding in Singapore.

Updating reporters on the traffic situation on Friday, ICA's Commissioner Eric Tan said the enhanced security measures were necessary for border security.

However, the ICA's slew of measures to ease congestion was paying off, he said.

These included opening more lanes to clear departing trucks and lorries, and deploying officers to ensure that queues are orderly and that motorcycles do not spill into lanes meant for other vehicles.

The ICA also started a trial on Monday to divert lorries to the Old Woodlands Checkpoint - which was decommissioned nearly a decade ago - for clearance in a bid to improve their waiting times.

It is also discussing with the Singapore Chinese Chamber of Commerce & Industry (SCCCI) to see how clearance could be expedited for empty trucks leaving Singapore.

These trucks - about 14 of them - arrive here with livestock such as ducks and chickens before leaving for Perak - 610km from Singapore.

'Allowing them to spend less time in the queue would allow the drivers to get a good night?s rest before making the journey here again,' Mr Tan said.